What Was in the World Trade Center Plume?

Scientific American wrote What Was in the World Trade Center Plume? "Asbestos may have been the least of health concerns from the gray smoke and fluffy, pinkish-gray dust created as the two towers collapsed, pulverizing cement, glass and everything else in the buildings. As a result, the EPA's Inspector General concluded in 2003 that the agency "did not have sufficient data and analyses to make such a blanket statement" about air safety and chided the White House Council on Environmental Quality and National Security Council for interfering with the process. And in those dust samples the EPA did collect and analyze in the first week after the attacks, 25 percent showed asbestos levels above the 1 percent threshold that indicates "significant risk," according to the EPA. "Competing considerations, such as national security concerns and the desire to reopen Wall Street, also played a role in EPA's air quality statements," the Inspector General concluded in a 2003 report [pdf].

Plus, inside the two towers were heavy metals, such as lead that helps make electric cables flexible and poisons the human brain, as well as polychlorinated biphenyls (PCBs) used in electrical transformers that are toxic on their own and become even more toxic when burned at high heat, and glass fibers that lodge in the lungs. The levels of dioxin measured in the air near the smoldering pile "were the highest ambient measurements of dioxin ever recorded anywhere in the world," levels at least 100 times higher than those found downwind of a garbage incinerator, according to an analysis published by EPA scientists [pdf] in 2007.

Ten years later, no one knows what was in the cloud of gases released by the combustion of all that jet fuel and building material but science has revealed what was in the dust—cement, steel, gypsum from drywall, building materials, cellulose from paper, synthetic molecules from rugs, glass fibers and human hair from the long decades of the two towers' use, among other items. "The [World Trade Center] dust held everything we consider near and dear to us," wrote Lioy, who carried out the first such analysis, in his book  Dust: The Inside Story of Its Role in the September 11th Aftermath (Rowman & Littlefield Publishers, 2010)."